Fuel in Oil

Forest#2

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Just little bit of info and you may already know this:
You say your replaced the carb and still seeing the same thing.
If the engine oil is really clean and even hot and thin you can sometimes get fooled by the oil level by eyeballing. Sounds strange but true. Try this method for getting a precise level as gauged on the dipstick. Take a white clean paper towel and when you remove the dip stick wipe oil off, re-install dipstick and then lay the dipstick on the paper towel with the white towel flat and the dipstick flat level. The oil will leave a exact oil mark impression on the towel. Do not drag the dipstick, just press against the paper towel.
If the gas is going into the intake manifold when you turn the engine off you can see such on that model if you will park the tractor level, take the air filter off and then take a flashlight and look into the carb throat about every 15 min's and you can see if any raw gas is in the manifold at the bottom of the carb If the needle and seat is leaking the engine will usually be hard to re-start after few min's because it's flooded. Also usually if the needle/seat is leaking on the old twin L-heads the engine won't idle good and you can see lots of gas coming out the carb ventura when the engine is idling.
To check the needle/seat on the old Briggs 3 screw and 4 screw carbs, remove the carb from the engine, use a mityvac and with the carb upside down apply 5 psi pressure and it should hold this pressure for long time. If not holding pressure do not immediately assume it's the needle/seat, use soap/water spray bottle and check the fuel pump edges and the pulse port. If no bubbles seen then go to the needle/seat area. A very slow leaking needle seat (1psi in 5 min's) usually will not flood a running engine or flood the crankcase if the gas tank fuel outlet is below the carb.

At same time you are removing the air filter pull the pulse hose off the bottom of the fuel pump on the bottom of the carb. Be careful here because if any gas drips out it will hit onto the hot exhaust area. If any gas at all comes out the fuel pump diaphragm is bad. If it's a 4 screw fuel pump I re-build them with the carb in place. If it's a 3 screw pump the carb needs to go to the work bench due to small springs, etc, inside.

You might consider draining the oil about 1/8 inch low on the dip stick with the engine level and then later when you check the level park the tractor in the same place. The oil level on those engines can vary by quite a bit by not being in same level position and also it's common thing to see a really high level after the engine has cooled.
Installing a white or red Briggs in-line fuel filter is a good thing on those engines.



Just curious?

What gaskets are you replacing?
 
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rancher_mac

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Just little bit of info and you may already know this:
You say your replaced the carb and still seeing the same thing.
If the engine oil is really clean and even hot and thin you can sometimes get fooled by the oil level by eyeballing. Sounds strange but true. Try this method for getting a precise level as gauged on the dipstick. Take a white clean paper towel and when you remove the dip stick wipe oil off, re-install dipstick and then lay the dipstick on the paper towel with the white towel flat and the dipstick flat level. The oil will leave a exact oil mark impression on the towel. Do not drag the dipstick, just press against the paper towel.
If the gas is going into the intake manifold when you turn the engine off you can see such on that model if you will park the tractor level, take the air filter off and then take a flashlight and look into the carb throat about every 15 min's and you can see if any raw gas is in the manifold at the bottom of the carb If the needle and seat is leaking the engine will usually be hard to re-start after few min's because it's flooded. Also usually if the needle/seat is leaking on the old twin L-heads the engine won't idle good and you can see lots of gas coming out the carb ventura when the engine is idling.
To check the needle/seat on the old Briggs 3 screw and 4 screw carbs, remove the carb from the engine, use a mityvac and with the carb upside down apply 5 psi pressure and it should hold this pressure for long time. If not holding pressure do not immediately assume it's the needle/seat, use soap/water spray bottle and check the fuel pump edges and the pulse port. If no bubbles seen then go to the needle/seat area. A very slow leaking needle seat (1psi in 5 min's) usually will not flood a running engine or flood the crankcase if the gas tank fuel outlet is below the carb.

At same time you are removing the air filter pull the pulse hose off the bottom of the fuel pump on the bottom of the carb. Be careful here because if any gas drips out it will hit onto the hot exhaust area. If any gas at all comes out the fuel pump diaphragm is bad. If it's a 4 screw fuel pump I re-build them with the carb in place. If it's a 3 screw pump the carb needs to go to the work bench due to small springs, etc, inside.

You might consider draining the oil about 1/8 inch low on the dip stick with the engine level and then later when you check the level park the tractor in the same place. The oil level on those engines can vary by quite a bit by not being in same level position and also it's common thing to see a really high level after the engine has cooled.
Installing a white or red Briggs in-line fuel filter is a good thing on those engines.



Just curious?

What gaskets are you replacing?
I got a complete gasket set off eBay that was just delivered. Going to replace different gaskets like the intake and spacer gaskets to the carb. Just figured that while I’m at it I might as well do this. There was gas inside the intake under the carb so I’m guessing something is still faulty with the carb. I’ll continue to dig and see what I come up with.
 

Forest#2

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Do the needle/seat test that slomo and I suggested.
Seeing raw fuel in the manifold is not a good thing. Probably needle/seat leaking.

Also install a 60-70micron fuel filter. You say you installed a NEW carb and it's still same O. The Briggs red filters are about 150 microns are ok for gravity feed and can be used on fuel pumps feeds but the white finer filters are about 60 microns for fuel pump small engines. Using a 60-70 micron can cause a engine to starve for fuel when under a heavy throttle load. Probably trash particles getting to the carb, could even be old fuel lines.
Sometimes just cutting a old fuel line to install a filter will send trash downstream between the filter and the carb.
 

rancher_mac

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Do the needle/seat test that slomo and I suggested.
Seeing raw fuel in the manifold is not a good thing. Probably needle/seat leaking.

Also install a 60-70micron fuel filter. You say you installed a NEW carb and it's still same O. The Briggs red filters are about 150 microns are ok for gravity feed and can be used on fuel pumps feeds but the white finer filters are about 60 microns for fuel pump small engines. Using a 60-70 micron can cause a engine to starve for fuel when under a heavy throttle load. Probably trash particles getting to the carb, could even be old fuel lines.
Sometimes just cutting a old fuel line to install a filter will send trash downstream between the filter and the carb.

I ran a new carb and yet again it was loading the intake again…that or I should have removed the intake first before testing it. Once I started uninstalling the intake manifold the low side of the intake dumped gas. I don’t have a mightyvac so I can’t text the needle right now. I’ll order a new fuel filter like you mentioned. Going to look at valves and head next and see how everything is looking for more general maintenance purposes.

Took valve lash measurements. Right - I: .003 E: .006 Left - I: .003 E: .008. Not too out of spec but running a little tight. Cylinder walls look great, can still see the crosshatch marks on both sides without any noticeable gouges. Some carbon in the left side intake (low side) so I'm guessing this is the excess fuel partially burning.

Screenshot 2023-06-20 172542.png
 
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Forest#2

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With the intake manifold showing raw gas the carb being tested has a leaking needle seat. You need to get that corrected before doing the other things.

If you don't have or want to purchase a Mityvac 8500 that does both vac and pressure you can find a blood pressure bulb on fleece bay for around $10 that will do the pressure test of the needle seat.
Sometimes you can inspect the needle tip under a magnifying glass and good light and clean the seat with a q tip.
Just a little hint. You might see two different brass seats in those carb kits, the one with the larger hole is for gravity flow and the small hole seat is for pressure feed.
I've ran those type carb's with the larger seat hole on those type carbs on their pulse pumps with no problem if they are good going in at first and using a white fuel filter and non-ethanol gas so as to keep everything clean.
 

rancher_mac

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With the intake manifold showing raw gas the carb being tested has a leaking needle seat. You need to get that corrected before doing the other things.

If you don't have or want to purchase a Mityvac 8500 that does both vac and pressure you can find a blood pressure bulb on fleece bay for around $10 that will do the pressure test of the needle seat.
Sometimes you can inspect the needle tip under a magnifying glass and good light and clean the seat with a q tip.
Just a little hint. You might see two different brass seats in those carb kits, the one with the larger hole is for gravity flow and the small hole seat is for pressure feed.
I've ran those type carb's with the larger seat hole on those type carbs on their pulse pumps with no problem if they are good going in at first and using a white fuel filter and non-ethanol gas so as to keep everything clean.
Thanks for all the tips and advice. I did replace all the fuel lines a few years ago, but I the filter is past due. I always use non-ethanol with some seafoam added to try to help keep everything clean. Try to keep the fuel system as clean as I can. I’ll look into trying to pressure test and see what I can come up with. Going to probably clean valves and cumbuation chamber over the next couple days and then I’ll be able to hopefully put back together this weekend or early next week. I would put it back together just to do the needle valve testing but I don’t have much spare time right now and have needed to do a thorough run through for over a year now.
 

rancher_mac

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Quick question. Got my hands on a pressure tester. How do I test these specific carbs? Having a hard time figuring it out…unless all the needle valves are bad and hold no pressure. Hooked it up to the inlet to the fuel pump on the carb but it won’t build pressure.
 

bertsmobile1

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Mac
Tip the carb upside down
Apply pressure
it should hold 3 psi for hours and pop off he seat between 7 & 15 psi with nothing more than the weight of the float holding it closed
You can not test it on the engine unless you are pumping a liquid in there to make the float lift up and seal against the seat
Only 1 needle & float in a carb
 

rancher_mac

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Mac
Tip the carb upside down
Apply pressure
it should hold 3 psi for hours and pop off he seat between 7 & 15 psi with nothing more than the weight of the float holding it closed
You can not test it on the engine unless you are pumping a liquid in there to make the float lift up and seal against the seat
Only 1 needle & float in a carb
Thank you. Set it and will check on it after a while.
 

rancher_mac

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How long should I leave it sitting to check for a leak? So far I’ve sat my carbs few hours each and saw no leak. I then sat one over night with a 1 psi drop over 10 hours.
 
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